Presence and localization of proteins immunologically related to erythrocyte protein 4.1 in human skin

Analogues of human erythrocyte protein 4.1 have been examined in the human skin by immunochemical techniques using anti-human erythrocyte protein 4.1 antibodies. Immunoblot analysis revealed that human epidermis contains 4.1-like proteins of 80 kDa and 78 kDa that cross react with anti-protein 4.1 antibodies. Analysis with immunofluorescence microscopy revealed that the plasma membrane of the human epidermal keratinocyte was stained intensively in the basal cells, whereas spinous cells were moderately stained. It is noted that eccrine sweat gland cells and ductal cells were also stained in the peripheral cytoplasma. Taken together, these results demonstrate that 4.1-like proteins are present in human epidermal keratinocytes, eccrine sweat gland cells and ductal cells. The present findings enable us to suggest that a membrane skeletal protein lattice might exist in these cells.     

Human hand impedance characteristics during maintained posture

Received: 23 June 1993 / Accepted in revised form: 15 September 1994     

Re-description and taxonomy ofpentanchus profundicolus smith & radcliffe, based on a second specimen from the philippines (chondrichthyes, carcharhiniformes, scyliorhinidae)

Pentanchus profundicolus is an enigmatic shark, characterized by a single dorsal fin. The holotype, which was collected in 1909 from the Philippines, had remained the only known example of the species for 90 years. A second specimen, collected from the same waters, is re-described. The presence of a single dorsal fin remains equivocal in so far as it represents the normal condition for the species. Aspects of the species' relationship with the species ofApristurus are discussed.     

A water channel of the nematode C.elegans and its implications for channel selectivity of MIP proteins

A genome project focusingon the nematode Caenorhabditis elegans has demonstrated thepresence of eight cDNAs belonging to the major intrinsic proteinsuperfamily. We functionally characterized one of these cDNAs namedC01G6.1. Injection of C01G6.1 cRNA increased the osmotic waterpermeability (P_f) of Xenopusoocytes 11-fold and the urea permeability 4.5-fold but failed toincrease the glycerol permeability. It has been speculated that the MIPfamily may be separated into two large subfamilies based on thepresence or absence of two segments of extra amino acid residues (~15amino acids) at the second and third extracellular loops. BecauseC01G6.1 (designated AQP-CE1), AQP3, and glycerol facilitator (GlpF) all have these two segments, we replaced the segments of AQP-CE1 with thoseof AQP3 and GlpF to identify their roles. The functional characteristics of these mutants were principally similar to that ofwild-type AQP-CE1, although the values of P_f andurea permeability were decreased by 39-74% and 28-65%,respectively. These results suggest that the two segments of extraamino acid residues may not contribute to channel selectivity orformation of the route for small solutes.

     

Pummerer Rearrangement of Selenium-Containing Uracil Nucleosides

Abstract

Pummerer-type rearrangement of uracil nucleosides having a phenylseleno group in the 2′-, 3′-, and 5′-positions took place upon oxidation with MCPBA in CH₂Cl₂ followed by treatment with acid anhydrides to yield α-acyloxyselenides.     

Coevolution and Hierarchical Interactions of Tomato mosaic virus and the Resistance Gene Tm-1

During antagonistic coevolution between viruses and their hosts, viruses have a major advantage by evolving more rapidly. Nevertheless, viruses and their hosts coexist and have coevolved, although the processes remain largely unknown. We previously identified Tm-1 that confers resistance to Tomato mosaic virus (ToMV), and revealed that it encodes a protein that binds ToMV replication proteins and inhibits RNA replication. Tm-1 was introgressed from a wild tomato species Solanum habrochaites into the cultivated tomato species Solanum lycopersicum. In this study, we analyzed Tm-1 alleles in S. habrochaites. Although most part of this gene was under purifying selection, a cluster of nonsynonymous substitutions in a small region important for inhibitory activity was identified, suggesting that the region is under positive selection. We then examined the resistance of S. habrochaites plants to ToMV. Approximately 60% of 149 individuals from 24 accessions were resistant to ToMV, while the others accumulated detectable levels of coat protein after inoculation. Unexpectedly, many S. habrochaites plants were observed in which even multiplication of the Tm-1-resistance-breaking ToMV mutant LT1 was inhibited. An amino acid change in the positively selected region of the Tm-1 protein was responsible for the inhibition of LT1 multiplication. This amino acid change allowed Tm-1 to bind LT1 replication proteins without losing the ability to bind replication proteins of wild-type ToMV. The antiviral spectra and biochemical properties suggest that Tm-1 has evolved by changing the strengths of its inhibitory activity rather than diversifying the recognition spectra. In the LT1-resistant S. habrochaites plants inoculated with LT1, mutant viruses emerged whose multiplication was not inhibited by the Tm-1 allele that confers resistance to LT1. However, the resistance-breaking mutants were less competitive than the parental strains in the absence of Tm-1. Based on these results, we discuss possible coevolutionary processes of ToMV and Tm-1.     

Inhibition of swarming motility of Pseudomonas aeruginosa by branched-chain fatty acids.

Pseudomonas aeruginosa is capable of moving by swimming, swarming, and twitching motilities. In this study, we investigated the effects of fatty acids on Pseudomonas aeruginosa PAO1 motilities. A branched-chain fatty acid (BCFA)--12-methyltetradecanoic acid (anteiso-C15:0)--has slightly repressed flagella-driven swimming motility and completely inhibited a more complex type of surface motility, i.e. swarming, at a concentration of 10 microg mL(-1). In contrast, anteiso-C15:0 exhibited no effect on pili-mediated twitching motility. Other BCFAs and unsaturated fatty acids tested in this study showed similar inhibitory effects on swarming motility, although the level of inhibition differed between these fatty acids. These fatty acids caused no significant growth inhibition in liquid cultures. Straight-chain saturated fatty acids such as palmitic acid were less effective in swarming inhibition. The wetness of the PAO1 colony was significantly reduced by the addition of anteiso-C15:0; however, the production of rhamnolipids as a surface-active agent was not affected by the fatty acid. In addition to motility repression, anteiso-C15:0 caused 31% repression of biofilm formation by PAO1, suggesting that BCFA could affect the multiple cellular activities of Pseudomonas aeruginosa.     

Involvement of protein kinase C in the phosphorylation of 46 kDa proteins which are phosphorylated in parallel with activation of NADPH oxidase in intact guinea-pig polymorphonuclear leukocytes

Two proteins (Mr 46,000, pI 6.4 and 7.0), the phosphorylation of which was increased by any of the membrane-perturbing agents in parallel with activation of NADPH oxidase in intact guinea-pig polymorphonuclear leukocytes in our previous study (Okamura, N., Ohashi, S., Nagahisa, N. and Ishibashi, S. (1984) Arch. Biochem. Biophys. 228, 270-277), were also phosphorylated in a cell-free system prepared from the leukocytes. The in vitro phosphorylation of these two proteins was stimulated by the addition of phosphatidylserine in the presence of higher concentrations of Ca2+ (300-500 microM). The phosphorylation was further increased when protein kinase C partially purified from guinea-pig brain was added to the system. At a low concentration of Ca2+ (about 10 microM), stimulation of the phosphorylation was not attained by phosphatidylserine alone but required the addition of diacylglycerol or phorbol myristate acetate. On the other hand, the increase in the phosphorylation was inhibited by H-7, an inhibitor for protein kinase C. These results indicate that protein kinase C is involved in the phosphorylation of the two proteins, which may be related to the superoxide anion production stimulated by various membrane-perturbing agents.     

Records ofApristurus herklotsi (Lamniformes,Scyliorhinidae) and discussion of its taxonomic relationships

Additional specimens of the rareApristurus herklotsi are reported, and the characteristic features of this species are discussed.A. herklotsi is concluded to be a distinct species, having a very long snout, a narrow distance between the nostrils, a long caudal fin, a short abdomen, numerous teeth on both jaws, and a low number of monospondylous vertebrae.A. herklotsi appears to be mature at about 44 cm in total length.